1. Field of Invention
The invention relates to a method for quality inspection and testing of a flat print product, to a device for realizing the method, and to a support element which can be used with the device.
2. Related Art
An optical control method for the further print processing is known from the international patent application publication WO2009/140779 A1. With this method, flat print products which are positioned on a conveying device are moved along a conveying section, passing at least one image recording unit which records images of the print products and at least a section of the conveying device. These images, which respectively represent actual values, are compared in an evaluation unit with desired values, wherein irregularities of the conveying device are detected and corresponding signals are generated. With a different image processing method according to the publication WO2009/140779 A1, the edges of a print product, positioned on the conveying device, are detected by moving the conveying device with the print product between an optical sensor and an illumination element. The print products rest on support surfaces with uniformly spaced perforations which are light-permeable. Owing to the illumination from one side, shadow images are generated on the other side of the conveying device which are then recorded by the image-detection device. As a result, the contours of the print products and possibly occurring irregularities in the conveying section, such as dirt particles, can be detected in the area of the support surface that is not concealed by the print product.
An optical position detection device is known from the international patent application publication WO2009/140778 A1. In the same way as disclosed in the publication WO 2009/140779 A1, this solution calls for the print products positioned on a conveying device to be guided through between one or several light sources and an image-detection unit. In the process, the contours of the print products are detected, wherein different algorithms are used for evaluating the recorded images.
To be sure, the use of this method and/or device for the position detection and the further print processing make it possible to detect the position of a print product on the conveying device and thus also permit an automatic detection of incorrect placements and/or of incorrect contours of a print product, for example in particular the detection of dirt deposited along the conveying section. However, it is not possible to detect errors and/or irregularities in the condition of the print product itself since the surface of the print product is invisible to the image detection unit.